A number of electronic systems today include electronic equipment that mounts to a wall of a home or business, or other similar surfaces. These systems can include telephone systems which have interface boxes popularly called NIDs, or network interface devices, and boxes used by cable television system suppliers. Advanced residential and business communications systems, such as those employing fiber optic cable to the homes or businesses, utilize boxes on the side of the home that may include significant active (power-consuming) circuitry.
Service providers usually mount equipment of this nature outside the house, preferably at the utility point entrance. In this way, the service provider is afforded access to the equipment without requiring the subscriber to be at home. Another reason why NIDs are mounted outside of structures is due to the number or size (or both) of conduits coupled to the NIDs. In other words, usually the number of cables connected to an enclosure of a NID makes it difficult to mount it inside a structure and to have the NID be aesthetically pleasing to the subscriber.
Related to the inclusion of power-consuming circuitry is bow power can be dissipated at the NIDs. Since power is dissipated in the boxes or enclosures for the NIDs, a significant amount of heat can be generated. This heat should be moved to the air outside the enclosure efficiently in order to prevent damaging temperatures from developing in the enclosure. In some types of equipment, heat fins are used for this purpose, but they are unattractive and thus cannot be used in front of this type of equipment. Also, in some cases, the enclosure could be exposed to direct sunlight. When this happens, heat sinks on the front of the unit can be more harmful than good since the fins may become heated by the sunlight and cause the heat fins to work in reverse by injecting heat into the enclosure instead of removing it.
In some cases, enclosures can be made large enough that adequate heat removal may be provided by simply having sufficient surface area to dissipate the heat. However, the trend is toward smaller enclosures with a higher concentration or denser electronic packaging that includes several heat-producing components. These numerous heat producing components tend to exacerbate the problems with this smaller enclosure approach.
Accordingly, there is a need in the art for a heat transfer system for relatively small enclosures of subscriber interfaces that can remove heat produced by electronics positioned within the enclosure in an efficient manner. There is a further need in the art for heat removal systems of subscriber optical interfaces that can substantially reduce heat transfer from the external environment to inside the enclosure of the subscriber interface. Another need exists in the art for producing a small heat removal system that efficiently removes heat from the inside of an enclosure and meanwhile, is aesthetically pleasing to the subscriber.